Timing controller for electric motors



June 24, 1930.

E. W. SEEGER TIMING CONTROLLER FOR ELECTRIC MOTORS I 2 Sheets-Sheet 1Filed July 18, 1927 INVENTOR. BY iw/m A TTORNEYS.

J1me 3 E. w. SEEGER 1,767,620

TIMING CONTROLLER FOR ELECTRIC MOTORS Filed July 18, 1927 2 Sheets-Sheet2 KS '5 G KS o B F H V L L 573i TDM IN VEN TOR.

BY EAwX/n w fi/eggm.

A TTORNEYS.

Patented June 24, 1930 UNITED STATES PATENT orrica EDWIN W. SEEGER, OFWAUWATOSA, WISCONSIN, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO CUTLER-HAMMER 1110., OF MILWAUKEE,

WARE

Application filed July 18,

This invention relates to improvements in timing controllers forelectric motors, and the invention relates more particularlyto'improvements in motor driven timing devices.

An object of the invention is to provide an improved and simplifiedtiming controller 1 of the aforementioned character.

Another object is to provide a timing con- .following description.

There are many instances wherein it is desired to provide for automaticcyclic control of electric motors including starting and running thereoffor a predetermined period and alternately stopping the same for apredetermined period,the period during whichthe motor is sto ped beingpreferably adjustable at will. or example, a timing device of thecharacter herein described may be applied to control of the drivingmotors of various types of automatic conveyers,-

automatic washing machines, extractors, and the like. 1

The accompanying drawings illustrate an embodiment of the inventionwhich will now 'be described, it being understood that varione changesmaybe made in the details of construction and operation of the deviceillustrated without departing from the spirit and scope of the inventionas defined by the appended claims.

In the drawings, Figure 1 illustrates schematically anddiagrammaticallym control system embodying the invention, and

Figure 2 is an across-the-line diagram of ihe circuits and connectionsillustrated in Referring more particularly to Fig. 1, the

WISCONSIN, A CORPORATION OF DELA- TIMING CONTROLLER FOR ELECTRIC MOTORS192". Serial No. 206,561.

reference character M designates a driving motor, the periods ofoperation and inoperation of which it is desired to control. Said motormay be arranged to drive aconve er, washing machine, extractor, or thelike ghot shown). Motor M as shown is adapted to be connected with linesL L of a polyphase supply circuit upon closure of main contacts S S ofan electromagnetic starting switch S; one terminal of said motor beingpermanently connected to line L". Switch S is provided with normallyclosed auxiliary contacts S and normally open auxiliary contacts S, Sand S for purposes hereinafter described. The motor circuit initiallycompleted through closure of.switch S includes suitable startingresistances R R whereas within a predetermined period thereafter, as

' determined by the adjustment of a timing relay TR, switch 2R isadapted to close its normally open main contacts 2R and 2R therebyproviding accelerating and running connections for the motor. As shownswitch 2R is provided with normally closed auxiliary contacts 2R andnormally open auxiliary contacts 2R. Also as shown the timing relay TRis' provided with normally open con tacts TR, and a pivoted contactor TRnormally engaging a contact TR but movable out of engagement with thelatter and into engagement with a contact TR, as hereinafter more fullydescribed.

The means for controlling the duration ofoperation of motor M maycomprise a limit switch LS in the form of a drum having a relativelylong conducting segment 10 and a relatively short insulating segment11,-the

latter being adapted to interrupt circuit through .co-operating contactfingers 12 and 13 upon rotation of said drum by motor M through suitablereduction gearing 14.

The means for controlling the period of inoperation of motor M includesa drum D having contact fingers a, b, 0, d and e adapted toco-operatewith corresponding segments (1 b 0 d and 6. Drum D is adaptedto be driven by a reversible pilot motor TDM,- reverse circuitconnections for said pilot motor being controllable by suitableelectromagnetically operable switches F and B serectivey with nonallyclosed auxiliary contacts and normally open auxiliary contacts F and Fwhereas switch B is likewise provided with normally closed auxiliarycontacts 13 and normally open auxiliary contacts B and B Completion ofan energizing circuit for pilot motor TDM is dependent upon priorclosure of a double-pole knife switch KS or the like; whereas the,single-pole knife switches KS KS and KS are respectively adapted whenclosed individually to determine the operating period of said pilotmotor.

in electromagnetically operable relay CR is also provided for purposeshereinafter de-' scribed; said relay having a pair of normally open maincontacts CR and CR and normally closed auxiliary contacts CR Gperationof the control system will now be described with particular reference tothe diagram of Fig. 2. Thus assuming positioning of the various elementsas illustrated, it will be seen that upon closure of knife switch KS anenergizing circuit is completed for the winding of switch F foreffecting operation of pilot motor TDM in one direction. Said circuitmay be traced from line L through the left-hand pole of knife switch KS,conductors 15,16, 17 and 18 through the normally closed auxiliarycontacts CH of relay CR, conductors 19 and 20 through normally closedauxiliary contacts B of switch B to and through the winding of saidswitch F, thence through normally closed auxiliary contacts 2R of relay2B, and by conductors 21, 22, 23 and the right-hand pole of knife switchKS to line L Switch F in closing completes a maintaining circuit foritself shunting the afore-mentioned auxiliary contacts CR saidmaintaining circuit extending from line L to conductor 16, thencethrough contact, fin ger a on drum D and conductor 24 through thenormally open auxiliary contacts F of switch F, conductors 25 and 20through the auxiliary contacts 13, and thence through the winding ofswitch F to line L as previously traced.

Also upon closure of normally open auxiliary contacts F of switch F anenergizing circuit is com leted for the winding of timing relay TR, saidcircuit extending from line L to contact finger a of drum D, thencethrough segments a and b of said drum to contact finger I), conductors26, 27 and 28 through said auxiliary contacts F thence through normallyclosed auxiliary contacts S of main switch S, through the winding ofsaid relay TR to conductor 21, and to line L as previously traced.

Relay TR thereupon operates immediately to efi'ect engagement of itscontactor TR with contact TR, thereby completing an ener izing circuitfor the winding of main switc S, said'circuit extending from line L toauxil- As shown switch F is provided iary contacts F as previouslytraced, thence by conductors 41 and 29 to said contact TR and contactorTR by conductor 30 through the winding of said switch S, and byconductor 21 to line L as previously traced. The main contacts S S ofswitch S in closing provide starting connections for main motor M, saidstarting circuit including resistances R R as will be obvious.

Switch S is also adapted upon closure of its normally open auxiliarycontacts S and S to provide a maintaining circuit for itself.

shunting the contact TR and contactor TR of relay TR, said shunt circuitbeing obvious. Also upon closure of normally open auxiliary contacts Sand S of switch S an additional or alternative maintaining circuit isprovided for the latter, said circuit extending from line L to conductor17 as previously traced, by conductor 31 to contact finger 12, thencethrough segment 10 of the contact drum driv-' en by motor M and tocontact finger 13 thereof, by conductor 32 to said auxiliary contacts Sand S", and through the winding of switch S to line L as previouslytraced.

Switch S in closing also effects opening of its normally closedauxiliary contacts S thereby interrupting the afore-described energizingcircuit for the winding of relay TR. Upon de-energization of relay TRthe contactor TR thereof tends to immediately assume its normal positionwherein it engages contact TR but re-engagement of said elements issubject to a delay throu h the action of down-dashing dashpot DP (Flg.1). However, re-engagement of contactor TR with contact TR is effectedafter apredetermined time interval, thus completing an energizingcircuit for the winding of accelerating switch 2R, said circuitextending from line L to and through auxiliary contacts S and S aspreviously traced, thence by conductor 30 to and through contactor TRand contact TR of relay TR, by conductor 33 throu h said winding, and bconductor 21 to line The main contacts 2 1 and 2E. of switch 2R inclosing short circuit resistances R and R respectively, therebyproviding for acceleration of motor M.

During the aforedescribed starting operation of motor M the segments a,'b etc. of drum D will have been moved slightly to the left of thepositions illustrated, due to o ration of pilot motor TDM in a forwardirection. This will slightly upset the initial timing operation of pllotmotor TDM and drum D, but the correct predetermined timing period willbe insured upon each succeeding o eration of the pilot motor. Thus uponclbsure of switch 2B in the manner aforedescribed the normally closedauxiliary contacts 2R thereof will be opened, thereby in- Similarly uponclosure of switch 2R the normally open auxiliary contacts 2R thereof areclosed to provide an energizing circuit for the winding of relay CR,said circuit extending from line L to conductor 17 as previously traced,thence through said winding of relay CR, conductors 34 and through saidauxiliary contacts 2R, and by conductors 21, 22 and 23 through theright-hand pole of knife switch KS to line L Upon closure of thenormally open main contacts CR of relay CR a maintaining circuit isprovided for the winding of the latter shunting the aforementionedauxiliary contacts 2R*,said shunt circuit being obvious. Also 11 )011closure of relay CR the main contacts SR thereof are closed to presetthe energizing circuit for the winding of switch B for completion uponoperation of timing relay TR in the manner hereinafter described.Similarly upon closure of relay CR ing effects reclosure of itsauxiliary contacts the normally closed auxiliary contacts CR thereof areopened, thus rendering completion of the initial energizing circuit ofswitch F subject to closure of one of the knife switches KS KS or KS andfurther subject to engagement of the corresponding segment 0, d, or ewith its co-operating contact finger c, d or e.

Thus after stoppin in the manner aforetfescribed the motor M continuesto operate for a period determined by the length of segment 10 of thedrum driven by motor M. However, when the insulating segment 11 isbrought into engagement with the contact fingers 12 and 13 theaforedescribed alternative maintaining circuit for switch S is interruted, and switch S opens to disconnect motor from the line; it beingnoted that the other maintaining circuit for switch S was interruptedthrough re-opening of normally open auxiliary con tacts F of switch F.The energizing circuit for the winding of accelerating switch 2B islikewise interrupted, and this switch in open- 2R thereby completin theaforementioned energizing circuit for t e winding of switch B; saidcircuit extending from line L to conductor 26, as previously traced, byconductor 27 through normall closed auxiliary contacts F of switchconductor 36 through said winding of switch B, contacts CR of relay CR(which is then in closed position as aforedescribed), thence byconductor 37 through auxiliary contacts 2R of relay 2B, and by conductor21 to line L as previously trace v Switch B in closing completes acircuit for pilot motor TDM to effect operation thereof in a reversedirection from that aforedescribed; whereas said switch in closingcompletes a ,maintaining circuit for itself (through its auxiliarycontacts B inde- Ipendently of the segment 6 of drum Thus of pilot motorTDM relay TR, said circuit extending from line L to contact finger a ofdrum D, thence to drum segments a, c and contact finger c, by conductor38 through said knife switch KS, conductors 39 and 40 through normallyopen auxiliary contacts B of switch B (which is 'then in closedposition), by conductor 41 through auxiliary contacts S of switch S,thence through the winding of said relay TR and by conductor 21 to lineL Relay TR in effecting engagement of its contactor TR with contact TRcompletesan energizin circuit for the winding 7 of switch S, sai circuitextending from line L to auxiliary contacts B as justtraced, thence byconductor 29 through contact TR and con- .3

tactor TR, conductor 30 through the winding of switch S, and thence byconductor 21 to line L. Switch S thereupon closes to again complete theenergizing circuit for motor M, whereas the normally open auxil- Y iarycontacts S and S of said switch in closing provide a maintaining circuittherefor shunting thecontacts of relay TR; said maintaining circuit asshown including the aforementioned auxiliary contacts B of switch B.Moreover, after closure of auxiliary contacts S and S of switch S, andupon movement of conducting segment 10 of limit switch LS into bridgingrelation to contact fingers 12 and 13, an alternative maintainingcircuit is provided which is independent of the auxiliary contacts B ofswitch B,said last mentioned maintaining circuit having been previouslydescribed.

Moreover, upon closure of switch S the auxiliary contacts S are 0 enedto interrupt the energizing circuit 0 relay TR. Deenergization of saidrelay efi'ects reopening of its contacts TR as will be obvious,- whereasafter a predetermined period (dependent upon the action of dashpot DP,Fig. 1) contactor TR engages contact TR to complete the energizingcircuit for the windin of accelerating switch 2R, rwith the resu tsaforedescribed. Likewise upon closure of switch 2R the auxiliarycontacts 2R thereof are opened, thereby interruptin the main- -0 of saiddrum when operation of pilot motor TDM is stopped. After a predeterminedperiod of operation of motor M the insulating segment 11 of limit switchLS engages contact fingers 12 and 13 to interrupt the energizingcircuits of switches S and 2B, as will be obvious,thus again stoppingsaid motor M. Moreover, under these conditions, upon de-energization ofswitch 2B the auxiliary contacts 2E thereof are closed, thus completingan energizing circuit for the grinding or switch F. Said energizingcircuit extends from line L to segment and contact finger c of drum D,conductor 38 through knife switch KS conductors 42 and through normallyclosed auxiliary contacts B of switch 3 {which is then in openposition}, thence through the winding of 5 :ch F and auxiliary contacts2R of switch 21%, and by conductor 21 to line L.

Thereupon switch F closes and provides a maintaining circuit for itswinding through auxiliary contacts F as aforedescribed. In this mannerpilot motor TDM is operated in a forward direction until the segment bof the drum D in moving toward the left again engages contact finger b;whereupon the aforedescrihed energizing circuit for the windin of relayTB is again completed, due to prior closure of auxiliary contacts T ofswitch F. Similarly such closure of timing rel y TR completes theinitial energizing circuit for the winding of switch S, and all of theoperations aforedescribed are repeated in sequence pending manualreopening of knife switch KS.

It will be noted that during operation of the system the drum segment bmoves to the right of contact finger 6 through a distance equal to theamount of movement required to eiiect engagement of segment 0 withcontact finger 0. Therefore the duration of operation of pilot motor TDMin a forward direction will be equal to the duration of operationthereof in the reverse direction. Moreover, it will be apparent from thefore oing that if either of the knife switches KS or K8 is closed whileknife switch KS remains open, the duration of operation of pilot motorTDM in a reverse direction may be definitEBr varied, (say, to sevenminutes or ten minutes) whereas the duration of operation of saidpilot'motor in a forward direction will be correspondingly varied.

While I have illustrated an arrangement of drum segments 0 d, candassociated knife switches KS KS and KS for preselecting the timeperiod of operation of the pilot motor (during which the main motor Mremains inoperative), it is to be understood that if desired the pilotmotor may be arranged to operate a single pair of contacts with anadjustable cam for obtaining different time intervals. v 7

Also while I have illustrated means for providing a fixed period ofoperation of main motor M it will be apparent to those skilled in theart that any suitable or well known means, such as adjustable conepulleys or a disk drive, may be provided for driving limit switch LS topermit variation of the operating period of said main motor.

What I claim as new and desire to secure by Letters Patent is:

1. In a motor control system, in combination, a unidirectionallyoperable main driving motor and a reversible pilot motor, each of saidmotors having a limit switch to be driven thereby, means operableautomatically upon normal positioning of the parts t complete an initialenergizing circuit for said pilot motor independently of said limitswitches, said means being thereupon also operable to complete an ener'zing circuit for said main motor and to e ect interruption of theenergizing circuit of said pilot motor, means for maintaining theenergizing circuit of said main motor pending a predetermined operationof the limit switch driven thereby, and means controlled by said lastmentioned limit switch and cooperating 'ith the limit switch of saidpilot motor to thereupon complete an energizing circuit for said pilotmotor to efiect operation of the latter in a reverse direction.

2. In a motor control system, in combination, a unidirectionallyoperable main driving motor and a reversible pilot motor, each of saidmotors having a limit switch to be driven thereby, means operableautomatically upon normal positioning of the parts to complete aninitial energizing circuit for said pilot, motor independently of saidlimit switches, said means being thereupon also operable to complete anener izing circuit for said main motor and to eflect interruption of theenergizing circuit of said pilot motor, means for maintaining theenergizing circuit of said main motor pending a predetermined operationof the limit switch driven thereby, and means controlled by said lastmentioned limit switch and cooperating with the limit switch of saidpilot motor to there upon complete an energizing circuit for said pilotmotor to effect operatlon of the latter in a reverse direction, saidlast mentioned limit switch including a pluralit of elements eachoperable selectively to pre etermine the duration of operation of sandpilot motor in opposite directions respectively. p

In witness whereof, I have hereunto subscribed my name.

EDWIN W. SEEGER.

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